An accurate service life prediction model is urgently needed for building joint sealants to reduce the enormous cost associated with long-term field weathering. A stepping stone to the success of this effort is the precise control of environmental variables in a laboratory accelerated test apparatus in order to produce reliable weathering data that can be used to generate and test the predictive model. This contribution reports a systematic study investigating individual and synergistic impacts of four environmental factors (cyclic movement, temperature, relative humidity, and ultraviolet radiation) on the durability of a model sealant system using a novel laboratory test apparatus. This apparatus is unique because it not only allows precise control of environmental factors, but it also permits in-situ characterization tests to be performed so the specimens need not be removed from the apparatus chamber. Graphical and quantitative statistical approaches were used to analyze the data. The study shows that the critical role of each individual factor as well as synergism among the different factors can be readily quantified and possible modes of degradation identified.
Citation: Journal of ASTM International
Pub Type: Journals
Sealant, Service Life Prediction, model, construction, modulus, SPHERE, Statistics